The mechanical advantage (amount of change in speed or torque) of connected gears is proportional to the number of teeth each gear has. Called gear ratio, it's the ratio of the number of teeth on the larger gear to the number of teeth on the smaller gear.  For example, a gear with 12 teeth connected to a gear with 9 teeth would have a gear ratio of 4:3.

Ceramics are mixtures of metallic and nonmetallic elements that withstand exteme thermal, chemical, and pressure environments. They have a high melting point, low corrosive action, and are chemically stable. Examples include rock, sand, clay, glass, brick, and porcelain.

f_Ad_A = f_Bd_B + f_Cd_C

For this problem, this equation becomes:

25 lbs. x 9 ft. = 45 lbs. x 2 ft. + f_C x 4 ft.

225 ft. lbs. = 90 ft. lbs. + f_C x 4 ft.

f_C = \( \frac{225 ft. lbs. - 90 ft. lbs.}{4 ft.} \) = \( \frac{135 ft. lbs.}{4 ft.} \) = 33.75 lbs.

Drag is friction that opposes movement through a fluid like liquid or air. The amount of drag depends on the shape and speed of the object with slower objects experiencing less drag than faster objects and more aerodynamic objects experiencing less drag than those with a large leading surface area.

Power is the rate at which work is done, P = w/t, or work per unit time. The watt (W) is the unit for power and is equal to 1 joule (or newton-meter) per second. Horsepower (hp) is another familiar unit of power used primarily for rating internal combustion engines. 1 hp equals 746 watts.